Technical Abstract:
Corn gluten meal is an environmentally friendly material that has demonstrated ability to decrease seedling development and plant survival by inhibiting root and shoot development. This discovery provides the opportunity to use CGM as an organic preemergence and preplant-incorporated herbicide. Unfortunately, CGM can also decrease the development and plant survival of direct-seeded vegetable crops. As a result, the use of CGM is not recommended in conjunction with direct-seeded vegetables. The development of equipment to apply CGM in banded configurations has created an opportunity to investigate whether banded CGM applications will provide significant crop safety for direct-seeded vegetables. The objective of this research was to determine the impact of banded corn gluten meal applications on squash plant survival and yields. This factorial field study was conducted during the summer of 2005 on 32-inch wide raised beds at Lane, OK with two application configurations (banded and solid), two CGM formulations (powdered and granulated), two incorporation treatments (incorporated and non-incorporated), and three application rates (5, 10, and 15 lb/100 ft2). The two CGM formulations at three application rates were uniformly applied in both banded and solid patterns on August 19. The banded application created a 3-inch wide CGM-free planting zone in the middle of the raised bed. The CGM applications were then either incorporated into the top 1 to 2 inches of the soil surface with a rolling cultivator or left undisturbed on the soil surface. 'Lemondrop' summer squash (Cucurbita pepo L.) was then direct-seeded into the center of the raised beds. When averaged across the other factors, there was no significant difference between powdered and granulated CGM formulations or incorporating and non-incorporating the CGM for either squash plant survival or yields. CGM application rates did affect crop squash survival and yields when averaged across all other factors. When averaged across all other factors, the banded application resulted in significantly greater crop safety (90% plant survival) and yields (180 cartons/a) than the broadcast (solid) applications (45% plant survival and 127 cartons/a). The research demonstrated the potential usefulness of CGM in direct-seeded squash production, if used in banded application configuration. Additional research should further investigate the interaction of CGM application rates and the width of the CGM-free zone on crop safety for various vegetables.